Compound steam-engine.



Patented NOV. 24, 1914.

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COMPGUND STEAM ENGINE.

APPLICATION FILED ssrnso, 1914.

Patented Nov. 24, 1914.

2 SHBETSS IIEBT 2.

W NR 0 7 T n THE NORRIS PEYERS CO.,IHO10-LIT)|O,. WASIHNGION. u I:

UNITE sra FFICE.

HUGO LENTZ, OF HALENSEE, NEARJBERLIN, GERMANY.

COMPOUND STEAM-ENGINE.

. Application filed September 30, 1914.

To all whom it may concern:

Be it known that I, HUeoLEN'rz, a citi- I ments in Compound Steam- Engines, of

whlch the followlng 1s a specihcatlon.

My invention relatesto compound steam engines.

. The invention is particularly useful in connection with compound engines of the Woolf type having steam distribution chests arranged separate from one another at the cylinder ends, each of which contains valves which control the flow of steam to and from the cylinders, all the valves being actuated by a lay shaft disposed transversely of the cylinders. I i

In the type of engine described the valvestem guides and thelay shaft casing were heretofore cast in one piece with the two cylinders. In order to be able to make this casting several pattern boxes were required and it was also necessary to insert a number of cores. This rendered not only the manufacture of the pattern but also the casting of such cylinder and its subsequent machining troublesome and expensive.

One of the objectsof my invention is to arrange and construct the valve operating mechanism in adurable and efficient man-, ner.

Another object of my invention is to obviate the difliculties which have arisen from having the valve stem guides and the lay shaft casing cast in one piece with the two cylinders. To this end I make the casing of the lay shaft and also the valve-stem guides as separate parts distinct from the cylinder casting proper. The steam chests mounted on the ends of the cylinder and also the cylinder itself then have anexceedingly simple and smooth shape, so that such a compound steam engine cylinder can be cast with a few pattern boxes. This advantage is felt particularly in the case of compound engines of the Woolf type having an intermediate valve between each two cylinders, because on account of the intermediate valve the two cylinders must be cast in one piece. In addition, the machining of such a cylinder is very simple because all the holes in it are located parallel to one another. Further, theseparation of the lay shaft casing and the valve-stem uides from the cylinder casting proper ren ers it possible not only Specification of Letters Patent.

Patented Nov. 24, 1914.

Serial No. 864,232.

to place the valves as compactly and close together as possible on the cylinders, for the purpose of procuring the shortest path for the steam, but also to make the lay shaft not materially longer than the diameter of the low-pressure cylinder. e

To these ends my invention consists in the construction, arrangement and combination of parts described hereinafter and pointed out in the claims.

Two illustrative embodiments of my incross-secti0n through the two cylinders taken on the line ll in Fig. 2. Fig. 2 a longitudinal section taken on the bent line 2-2 in Fig. 1, and Fig. 3 a cross-section takenon the line 33 in Fig. 2; Figs. 4 and 5 relate to a marine engine of the type described, the cylinder covers having been removed, Fig. i being a cross-section through the cylinders of the engine, the upper half being a section taken on the line l--4-4 and the lower half a section taken on the line 4l-4---l in Fig. 5, and Fig. 5 is a section taken on the line 5-5 in Fig. l.

Referring ,firstly to Figs. 1 to 3, at each end of the high-pressure cylinder a and of the low-pressure b is arranged a steam distributing chest 0 common to the two cylinders, and the steam enters at 9 into and issues at it out of this chest. By means of suitably arranged Walls in these steam chests passages are formed through which the steam can pass from the admission branch 9 through the inlet valve (Z into the highpressure cylinder a, from this through the intermediate valve 12 into the low-pressure cylinder 1) and from this through the ex haust valve 7 into the exhaust branch lb.

The valves d, e and 7' are actuated by the lay shaft Z located in the bore m in the easing 2'. v This casing '21 is a member separate from the cylinders, as also arethe valve- I stem guides which are formed as separate tubular boxes or bushes in in which are mounted the valve stems 1' whose ends coact with cams milled in the shaft Z. These boxes 7: are introduced through the ends of the valves into the casing z' in such manner that the latter is held by the boxes and requires to be screwed to the projections a',b of the cylinder with only a small surface contact: ing with it. In such a construction that part of the cylinder casting which is most difficult to mold and to cast is done away with, namely the transverse lay shaft casing, which has heretofore been cast with the cylinder, and the valve-stem guides disposed longitudinally thereof. An exceedingly simple cylinder casting results which can be made with only a few patterns and readily admits of manufacture on duplication methods. In addition, it is possible to place the valves mounted in the distributing chests as near as possible to the cylinders, which arrangement is particularly favored, on the'onehand, bythe large exhaust valve being located in the free space between the high and low pressure cylinders and, on the other hand, by the lay shaft or the lay shaft casing i being'not substantially longer than the diameter of the low-pressure cylinder, sotha' t it can be better adapted to the cylinders and accommodated close above the high-pressure cylinder in the box shaped space which is bounded below by the highpressure cylindera, on each side by the two distributing'chestsc and on the'end by'the low-pressure cylinder Z). This arrangement nevertheless admits of the short lay shaft being conveniently removed laterally toward the high pressure side. This is exceedingly advantageous in locomotive engines because in these the high-pressure cylinder is generally located outside or can be readily placed there, and the hereindescribed construction assures ready accessibility of the lay shaft,particularly from this side, and a simple drive ofthe same. The valves and valve stems can also be readily removed because the covers of the valve chests are completely exposed.

' Owing to the compact construction enabled according to my invention in combination with the short steam passages and the short bores, and owing to the arrangement of th'e memb'ers driving the valves in casings made separate from the cylinders the radiating surf-aces are-reduced to a minimum inasmuch as the valve-stem guides made separate from the cylinder castings are completely exposed and therefore can heat only little and'can transmit only little heat.

The same advantages can be obtained in marine engineshaving vertical cylinders as will be understood from Figs. 4 and 5 in which those parts which correspond to like parts in the embodiment described above aredesignated by like reference letters. The only -'clifi'erence between this marine engine andthe construction described above is that the lay shaft casing passes transversely through the free space between the high pressure cylinder-a and the low-pressure cylinder b separatethere-from, and is attached in suitable manner to the low-pressure cylinderb. The lay shaft casing 71 is connected in the manner described above by the valvestem boxes 7: with the distributing chests c which in this case constitute the sole mechanical connection of the two cylinders. The valve stems are located parallel to the cylinders in a plane located at right angles to the middle plane common to the two cylinders. This construction also assures a simple cylinder casting and results in short steam passages and a short lay shaft casing which need not be materially longer than the diameter of the low-pressure cylinder. The entire valve gear is also readily accessible because both the valve covers and also the lay shaft are located between the feet g) of the cylinders.

I claim 1. In a compound, steam engine the'combination of a plurality of cylinders having connecting end members provided with passages for the flow of steam from one cylinder to the other, valves, controlling the flow of steam through said passages, valve spindles disposed longitudinally of the cylinders for operating said valves, a lay shaft disposed transversely of the cylinders intermediate the ends thereof and having ineans for operating the spindles, and a supporting casing for the lay shaft formed separate from the cylinders and detach-ably supported therefrom.

2. In a compoundsteam engine the combination of a plurality of cylinders having end members each provided with passages for the flow of steam fromo'n'e cylinder to the other, valves located in said passages and controlling the flow of steam through the same, reciprocating valve spindles extending from the valves longitudinally of the cylinders toward the middle thereof, a lay shaft disposed transversely of thesp-indles at the adjacent ends thereof and having means for operating the same, a supporting casing-for the lay shaft formed separate from th-e'cylinders, and spindle guides formed separate from the cylinders and from said supporting casing and detachablysecuring the l-atterto said end members of the cylinders.

3. In a compound steam enginethe combination of a plurality of cylinders having common end members connecting the adjacent ends of the cylinders and provided with a plurality of passages for the flow of steam from one cylinder to the other, a plurality of valved ports through whichsaid passages communicate, said ports being all located substantially to one side ofthe low pressure cylinderand'above the high pressure cylinder, valves controlling said ports, valvespindles extending from the valves 'longitudif nally of the cylinders and toward-the middle of the same, and a lay shaft disposed transversely of the high pressure eylinderto one side thereof adj-acent the-inner iend-s of the valve spindles andha'ving means'fo'r 'operat- 7 1 130 ing said spindles.

4. Ina compound steam engine the combination of a plurality of cylinders having commonend members connecting the adjacent ends of the cylinders and provided with a plurality of passages for the flow of steam from one cylinder to the other, a plurality of valved ports through which said passages communicate, said norts being all located substantially to one side of the low pressure cylinder and above the high pressure cylinder, valve controlling said ports, valve spin dles extending from the valves longitudinally of the cylinders and toward the middle of the same, a lay shaft disposed transversely of the high pressure cylinder to one side thereof adjacent the inner ends of the valve spindles and having means for operating said spindles, and separate supporting and guiding means for said lay shafts and for the valve spindles.

5. In a compound steam engine the combination of a plurality of cylinders having common end members connecting the adjacent ends of the cylinders and provided with a plurality of passages for the flow of steam from one cylinder to the other, a plurality of valved ports through which said passages communicate, said ports being all located substantially to one side of the low pressure cylinder and above the high pressure cylinder, valves controlliu said ports, valve spindles extending from t e valves longitudinall of the cylinders and toward the middle of the same, and a lay shaft disposed transversely of the high pressure cylinder to one side thereof adjacent the inner ends of the valve spindles and having means for operating said spindles, said lay shaft extending toward the low pressure cylinder, a supporting frame for the lay shaft formed separate from the cylinder and its end members, se' arate tubular guides for the different spin les telescoping at their ends with the end members of the cylinders and with the lay shaft casing.

In testimony whereof, I afiix my signature in the presence of two witnesses.

HUGO LENTZ.

Witnesses:

HENRY HAsPnR, WOLDEMAR I'IAUPT.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, I). 0. 

